You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

engine break in question

Hey we just to delivery of our new 2014 GT/CS it had 12 miles on it! Well we have driven it a little. We now have 125 on it. We are planning on taking it on a trip to florida, next weekend, which oneway is around 800 miles and about 11 hour drive. We usually take the drive pretty straight only stopping for gas and meals. I realize this is a new engine Im concerned about driving for long periods of time at least 3 or 4 hours or so between stops. Anything I should concern myself with being that it hasnt been full broken in yet?

This ad is not displayed to registered or logged-in members.Register your free account today and become a member on Mustang Forums!

I'm going to disagree with the potentially dangerous advice given by jz78817 and so does Ford. On page 208 of the 2014 Mustang Manual (3rd Edition), there is a section called, wait for it jz, 'Break In.'

[Begin Quote] Avoid driving too fast during the first 1000 miles (1600 kilometers). Vary your speed frequently and change up through the gears early. Do not labor the engine. [End Quote]

Do not use the cruise control for the first 600 miles or so in order that you vary your engine speed. Drive it briskly but don't hot rod it yet. I went to Nashville the first day I had my Mustang, and I would off ramp and on ramp every few exits and vary my speed, but then back off all of that craziness as the miles add up. Here is why:

The goal of modern engine break-ins is the settling of piston rings into an engine's cylinder wall. A cylinder wall is not perfectly smooth but has a deliberate ever-so-slight roughness to help oil adhesion. As the engine is powered up, the piston rings between the pistons and cylinder wall will begin to seal against the wall's small ridges.

In the past, the engine break-in period was very important to the overall life and durability or the engine. The break-in period required has changed over the years with improved piston ring materials and designs, but the basic principles of doing it, as you can tell from the Ford manual, remains the same. And, it is harder to screw it up now because modern engines come from the factory with much tighter tolerances than they did three decades ago when I was breaking in my Honda CB900F Super Sport.

The best explanation I've heard was by M.I.T. engineers Tom and Ray Magliozzi on the popular National Public Radio show, Car Talk, they say the issue is properly “seating the piston rings.” Here's their very informed answer during a casual discussion:

Tom: What does that mean? Well, at the heart of the engine are your pistons. They look like soup cans, and they go up and down inside the cylinders. It's crucial that there is a perfect, tight fit between the outside of the pistons and the inside of the cylinder walls.

Ray: So, the pistons are surrounded by spring-loaded rings, which push out against the walls and keep the seal tight. Otherwise, oil will get past the rings, and you'll "burn oil."

Tom: And the theory of "break in" is this: If the rings and the cylinder walls don't come out of the factory matching up perfectly, the break-in period gives them a chance to conform to each other during relatively "light duty" service, which involves going slowly and varying the speed.

Ray: Why is it 1,200 miles on one car, and 600 on another? Because it's not an exact science. I think each manufacturer is making its best guess as to how much time the rings will need. It's probably based on how many people have whined to them in the past about their cars burning oil. They look at their warranty claims and say, "OK, guys, let's jack it up another 200 miles and see if that helps."

Tom: It's interesting to note that some carmakers are so confident in their precision manufacturing that they require no break-in period at all.

Here’s the typical break-in advice published by one major car manufacturer:

“A long break-in period is not required for the engine in your vehicle.

“Drive moderately during the first 300 mi (500 km). After the initial 60 mi (100 km), speeds up to 50 or 55 mph (80 or 90 km/h) are desirable.

“While cruising, brief full-throttle acceleration, within the limits of local traffic laws, contributes to a good break-in. Wide-open throttle acceleration in low gear can be detrimental and should be avoided.”

Pretty “middle-of-the-road,” isn’t it? That’s because engine break-in isn’t the big deal it once was. To get a bit technical, that’s because engine manufacturers are able to hone the cylinders with far greater precision. Where cylinder clearances used to be in the thousandths of an inch, now they are in the ten thousandths. Bores are rounder and straighter. That means the pistons and the rings fit better, and that means there is less need for “wearing-in” the parts. There’s less friction, less heat buildup and less chance of improper seating of the piston rings.

Most experts agree that the “golden rule” in breaking in your new car is to warm up the engine before running it hard. That doesn’t mean idling for any length of time – not necessary! It does mean “taking it easy” the first few miles until you see the needle on the temperature gauge moving into the “normal” zone.

The process of engine break-in starts with low revs and about one-quarter throttle. Gradually, you rev a little higher and add a little more throttle. During this period, don’t keep the engine revs high for a long time. The idea is to gradually use more and more of the rev range, allowing the engine parts to wear-harden over time. The break-in for today’s engines is generally 700 to 1,000 miles.

One thing that hasn’t changed with engine break-in is the need for an early oil change. While the recommended oil change intervals for modern cars and trucks have been extended, the break-in oil and filter change should occur around 1,000 miles. This will clean out any fine metal particles dislodged in the first miles you put on your new car. Once those are out of the engine, you should be good to go, and go and go.

I'm going to disagree with the potentially dangerous advice given by jz78817 and so does Ford. On page 208 of the 2014 Mustang Manual (3rd Edition), there is a section called, wait for it jz, 'Break In.'

That must be why my engine blew up at 3,000 miles. Oh, wait, it didn't. But surely that's why it burns a quart of oil every 500 miles. Oh, wait, it doesn't.

"potentially dangerous."

Quote:

The process of engine break-in starts with low revs and about one-quarter throttle. Gradually, you rev a little higher and add a little more throttle. During this period, don’t keep the engine revs high for a long time. The idea is to gradually use more and more of the rev range, allowing the engine parts to wear-harden over time. The break-in for today’s engines is generally 700 to 1,000 miles.

that's just asinine. you think when fleets buy work trucks, they waste the time and money driving them gingerly around for weeks until they're "broken in?" No. They buy them, have them kitted out, and they start working their asses off right away.

that's just asinine. you think when fleets buy work trucks, they waste the time and money driving them gingerly around for weeks until they're "broken in?" No. They buy them, have them kitted out, and they start working their asses off right away.

We're not talking about work trucks or commercial fleets, was that an attempt to make us forget what you said above regarding the Ford Mustang GT in question? Even Ford disagrees with you by virtue of their Mustang Owner's Manual, Section Header, "Break-In", Page 208.

But if we were talking about fleets, congratulations, you're wrong about that too: many fleets have break-in protocol for new vehicles including law enforcement agencies like the one I serve, for our Tahoes, Explorers and cars.

Thanks, I have been flipping through the manual did not come across a break in section yet. But now I know its there I will read through it thoroughly. We took it for a drive yesterday and last night also we are now up to 250 miles. We are also gonna take it on another nice drive today. Thanks for the info!

Although today's engines don't necessarily require break-in like they did 20-40 years ago, just drive with a little bit of caution but don't baby it. I'd vary the cruising speed and duration with a few... "spirited"... jaunts to 90 or 100 mph if you have the stomach (my 4.6L saw 130 for the first of many times in the first 600 miles). Do you think they roll off the assembly line and are tested by someone's grandmother?

Although today's engines don't necessarily require break-in like they did 20-40 years ago, just drive with a little bit of caution but don't baby it. I'd vary the cruising speed and duration with a few... "spirited"... jaunts to 90 or 100 mph if you have the stomach (my 4.6L saw 130 for the first of many times in the first 600 miles). Do you think they roll off the assembly line and are tested by someone's grandmother?

every car comes off of end-of-line and goes over to the rolls (chassis dyno.) After a diagnostic check it goes up on the rollers and the tech runs it up to an indicated 60 mph and coasts down, then gets another diagnostic check. I can assure you they don't do that gently.

every car comes off of end-of-line and goes over to the rolls (chassis dyno.) After a diagnostic check it goes up on the rollers and the tech runs it up to an indicated 60 mph and coasts down, then gets another diagnostic check. I can assure you they don't do that gently.

Do they run wide open throttle right up to redline and bang off the rev limiter for a few seconds? Not really sure what your point is there.

This forum is owned and operated by Internet Brands, Inc., a Delaware
corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford
Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor
Company